After the Forge's primary and secondary bases were destroyed, they based themselves in a high-tech skyscraper. The 200 floor building looked "like a sliver of ice". It dominated the skyline of the city it was in.
The majority of the building was designed for the comfort of its inhabitants. The walls of its hallways were pastel-coloured and the floors were lined with a plush carpet. The basement was where the building's security computer was kept. Unlike the rest of the building, the basement was composed of bright metallic corridors which were reminiscent of the Forge's previous bases. The basement had doors which were made of Huldran ore and used Martian technology. (PROSE: Twilight's End)
After the Forge Beta Facility was destroyed, William Abberton was salvaged from the wreckage and was grafted with Oracle. This fusion of xenotech and humanity was the most advanced computer system in the world and was put in control of the skyscraper.
The computer could monitor the building's humidity, temperature, structural stress, and energy consumption and the heartbeats and blood temperature of all living things in the building. External sensors detected everything in the surrounding airspace.
During the time the Forge was based in the skyscraper, it gained enough power to break away from the British government and became the most powerful and influential conglomerates on Earth.
In the 22nd century, decades after Abberton fused with Oracle, he became tired of life and subconsciously sent a telepathic signal to the Seventh Doctor. The Doctor materialised his TARDIS in the building and was guided by Abberton to the basement. In the basement, the Doctor talked with Abberton and gave him the antidote to the Twilight Virus. Abberton helped the Doctor get safely back to his TARDIS and was left with a choice: to continue being the Forge's security system or to take the antidote and die. (PROSE: Twilight's End)